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

Annotations already declare a non-read-only, non-destructive, closed-world mutation; the description adds material context beyond that: the required scope, that locale-primary is mandatory, that version is always 0, and that nothing is published as a side effect. That is exactly the extra behavioral information an agent cannot get from the annotation hints.

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?

Front-loaded with the action, data shape, and outcome, followed by a clearly bracketed policy block. The policy block is generic boilerplate that runs long relative to the tool-specific content, but nothing is redundant with the earlier sentences.

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 3-required-param mutation with no output schema, the description covers the gaps that matter: return values (id, version 0, op_id), the required scope, the shape of the nested data object, and the follow-up path to publishing. An agent has everything needed to call it correctly.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning: the nested shape { <locale>: { <field>: value } }, the rule that the primary locale is required, and how to discover valid fields via get_schema → collections[].fields. Only the `site` and `collection` params are left entirely to the schema.

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?

States a specific verb and resource ("Create a CMS entry as a draft") plus the key scope required (content:write) and the exact return payload. It is clearly distinguishable from siblings like update_entry, publish_entry, and get_entry.

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?

Explicitly says publishing never happens here and routes the agent to get_entry_preview then publish_entry, giving the full draft→check→publish workflow. It also states the consent precondition (only when the user explicitly asks) and names the alternative tools by name.

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