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

The description explicitly says 'MUTATES YouCanBookMe data,' matching and reinforcing the destructiveHint annotation. It also adds useful behavior beyond annotations: the HTTP method/endpoint and that profileId is path-only and never sent in the body.

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 dense sentences provide the mutation warning, endpoint, required parameter, calendar lookup hint, passthrough usage, and path/body distinction with no filler. The most important constraint is front-loaded.

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?

The description covers the call pattern, required inputs, calendar linkage, and the fields passthrough mechanism. Since there is no output schema, it could mention what the response contains, but for a straightforward create operation the provided detail is sufficient for an agent to invoke it correctly.

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 already 100%, so the baseline is 3. The description adds value by explaining that name is required, that calendarId links to a calendar discoverable via list_available_accounts, and that fields is a passthrough for email, description, pic, and similar properties.

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?

The description clearly states the verb and resource: 'adds a team member to a profile,' and cites the exact YCBM POST endpoint. This distinguishes it from siblings like list_team_members and update_team_member.

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?

It gives clear context for using the tool, including that calendarId should be found via list_available_accounts. It does not explicitly state when not to use it or contrast with update_team_member, so it stops just short of full routing guidance.

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