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

Annotations cover write vs. read and idempotency, but the description adds substantial context beyond them: whole-payload replacement semantics, explicit null requirements, a 3-per-calendar-month quota for date/gender/known-hour changes, which edits are quota-free, and the fact that the quota count is exposed by a sibling tool. This is behavior an agent could not infer from the structured fields.

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 replacement semantics, null handling, update workflow, and quota — every sentence carries needed information. It is dense and slightly run-on, but nothing is redundant with the schema or title.

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 six-parameter write with no output schema, the description covers everything an agent needs: replacement semantics, null conventions, the read-merge-write update path, rate limits with an escape hatch, and the return payload ('Returns the element profile'). Nothing material is 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 coverage is 100%, so the baseline is 3. The description goes beyond it by explaining the explicit-null convention ('hour: null' for unknown time, 'gender: null' for unspecified) and the all-fields-required replacement rule, plus the cross-field constraint that minute requires hour. It doesn't add format details for year/month/day, but the schema already handles those.

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: 'register the user's birth date/time/gender'. It also names the relevant sibling (intentions_get_profile) for the update path, so an agent can distinguish writing the full profile from reading it without opening either schema.

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 to call once, that each call is a full replacement requiring all 6 fields, and precisely which sequence to follow for a single-field update (fetch via intentions_get_profile, merge, resend). It even scopes the rate limit to specific field changes, leaving no ambiguity about when this tool is the right choice.

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