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

Goes meaningfully beyond the annotations by disclosing that changes persist to the database, that the cache is invalidated, that the call is free (no coin cost), and that auth plus ownership are required. Given destructiveHint=true, it would be stronger if it warned that supplying word_clue_pairs replaces the existing set rather than merging.

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?

Three tight sentences, front-loaded with the operation and editable fields, followed by side effects and access requirements. No wasted wording.

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 mutation tool with no output schema, it covers persistence, cache invalidation, cost, and authorization. The main gap is not stating whether omitted fields are left unchanged — important for a partial-update tool with destructiveHint=true.

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%, so the schema already documents all five parameters including formats like [width, height] and easy/medium/hard. The description's field enumeration adds little beyond the schema and doesn't clarify partial-update semantics for omitted fields.

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 (edit existing crossword puzzle) and enumerates the editable fields (title, word-clue pairs, grid size, difficulty). The word 'existing' implicitly separates it from create_crossword, though no sibling is named explicitly.

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?

'Edit existing crossword puzzle content' plus 'Requires authentication and ownership' gives the prerequisite context for use. However, it doesn't explicitly say when to use this versus create_crossword or other edit_* tools, nor does it exclude any scenarios.

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