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

Adds substantial context beyond the annotations: appends to the end, 100-task cap, flat list with no subtasks, and the concrete consequence of non-idempotency ('calling this twice adds the tasks twice'), which explains what idempotentHint=false actually means. Also flags the 'never show IDs to users' presentation rule.

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 core action, then ordered supporting facts (ID source, item shape, limits, idempotency, alternative, display rule). Dense with zero filler 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 2-parameter append tool with no output schema, it covers constraints, idempotency, prerequisites, and alternatives thoroughly. It omits any hint about the response shape or ordering feedback, which is minor.

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 baseline is 3. The description restates that each item has text plus an optional category as 'the section heading it appears under', but adds little syntax or format detail beyond what the schema already documents.

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+resource+scope: 'Add one or more tasks to the end of an existing trip checklist.' The appended-at-end behavior and 'existing checklist' qualifier distinguish it cleanly from checklist_item_update, checklist_items_reorder, checklist_items_remove, and segment_create.

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?

Gives a prerequisite (get checklist_id from trip_checklists) and routes to the right alternative for creating a checklist ('use segment_create (type Note, isChecklist true)'). It does not spell out an explicit when-not-to-use case, but the sibling routing is clear and actionable.

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