Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it is a validation step that returns 'server-computed consequences plus the preview_token', and it explicitly states 'Nothing is modified'. It also discloses the content format constraint (AHM: no tables, colors, alignment, discussions, or file attachments). The only minor gap is not describing what the server-computed consequences look like, but the description carries substantial behavioral weight beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single dense paragraph that front-loads the most important fact ('REQUIRED first step') and the core behavior ('validates... returns...'). Every sentence earns its place: the first sentence covers purpose and output, the second covers safety and content format, and the third covers prerequisites. It is slightly long but information-dense, and the structure is logical. It could be split into two sentences for readability, but it is not bloated.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a validation tool with no output schema, the description explains the purpose, the required inputs' provenance, the content format, and the relationship to update_description. The main missing piece is a description of the return value shape (what 'server-computed consequences' looks like), but the description explicitly names the preview_token as the key output and points to get_ahm_spec for format details. Given the tool's complexity (4 required params, nested operations array) and the absence of an output schema, the description is nearly complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 75%, so the schema already documents most parameters. The description adds meaning by explaining the provenance of document_version ('from get_card / get_epic') and the source of block ids, which is not in the schema. It also clarifies that operations are 'applied in order against the evolving description', which adds semantic context to the operations array. The description does not repeat parameter names, and it compensates for the 25% gap by explaining where the required values come from.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('validates'), a specific resource ('card or epic description edit'), and its role as the 'REQUIRED first step' before update_description. It clearly distinguishes itself from the sibling update_description by explaining it returns the preview_token that update_description requires. The scope is unambiguous and an agent can tell it apart from other preview/update tools without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says when to use it ('REQUIRED first step of every card or epic description edit'), what it does not do ('Nothing is modified'), and what prerequisites exist ('read get_ahm_spec first; block ids and document_version come from get_card / get_epic'). It also names the dependent sibling (update_description) and the source tools for required parameters. This is explicit when/when-not guidance with alternatives and prerequisites.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.