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

Annotations already declare non-readOnly, non-destructive, non-idempotent, closed-world, so the description's job is the extra context; it does contribute the write-permission precondition and the required-field constraint. It says nothing about duplicate detection, what happens when a linked name is ambiguous (that is only in the schema), or what a successful call returns.

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 short sentences with the scope and the required fields front-loaded. The final sentence ('lay out the logistics for a day of filming') largely paraphrases the first, a small redundancy but not harmful.

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 14-parameter creation tool with full schema coverage and no output schema, the description supplies the permission precondition and required inputs, which is most of what the schema does not. The linking-by-name matching behavior and its ambiguity failure mode live only in the schema, so the description is adequate rather than 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 100%, and the individual parameter descriptions already cover naming conventions, date format, name-vs-id fallback, and add-only linking semantics, so the schema carries the burden. The description only restates that title and date are required, which the schema's required array already declares.

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 pair ('Plan a shoot day') and scopes it to a project the user can write to. It never explicitly contrasts with update-shoot-day or get-shoot-day, so sibling differentiation is implied by the name rather than stated in the description.

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?

'Use this to lay out the logistics for a day of filming' gives an implied usage context, and 'inside a project the signed-in user can add to' adds a permission precondition. There is no explicit when-not-to-use guidance and no named alternative for modifying an existing day rather than creating one.

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