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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: contentBudget is present in every response including empty cards, the cap is 12, and it counts ONLY this card, not children's entries. That is non-obvious behavioral context an agent could not get from the schema.

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 returned fields, then the distinguishing contentBudget behavior. It is dense with parentheticals and em-dashes but each clause carries real information; only mild compaction is possible without losing meaning.

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?

With no output schema and a read-only tool, the description carries the burden of describing returns and does so thoroughly, including the contentBudget triple and its 12-cap semantics. Nothing an agent needs to call and correctly interpret this tool appears missing.

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 100% and both parameters (cellId, expectedProjectId) are documented in the schema itself. The description adds no param-level detail beyond noting the parent-dependency ID format, which concerns returned data rather than inputs, so the baseline 3 applies.

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?

Opens with a specific verb+resource ('Returns the full details of a block') and then enumerates exactly what is returned: properties, children, contentBlocks, people, dependencies, parent structural dependency, and contentBudget. An agent can distinguish this read-detail tool from update_cell/add_content_block siblings from the description alone.

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?

Usage is implied rather than stated: the contentBudget framing ('enough to decide "add here or create a child block" ahead of writing') signals this is a pre-write inspection tool. However, no sibling alternative is named (e.g. search_cells vs get_full_data), and no explicit when-not-to-use guidance is given.

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