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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), so the safety burden is partly lifted. The description adds the add/remove delta semantics for interests and services, but omits key behavior for a mutation: whether omitted fields are left untouched, whether removals are reversible, and any permission requirements.

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?

Two compact sentences, front-loaded with what gets updated. The second sentence is useful but partially redundant with the schema's own id-acquisition notes, so it is not quite maximally efficient.

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?

An output schema exists, so return values need no explanation, and annotations cover the safety profile. However, for a 17-parameter mutation over nested additional_fields, the description leaves the partial-update contract and the interaction between add_/remove_ arrays unspecified — an agent still has to guess at those.

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 53% with 17 parameters; the highest-risk ones (add_interest_ids, add_services_needed/offered, additional_fields) already carry detailed schema descriptions, including the null-to-remove rule for additional_fields. The description's only parameter help — pointing at read_interests/read_services for ids — duplicates what the schema already says, and it adds nothing about field-level update semantics.

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 (update) plus the resource (one attendee in an event) and enumerates the field groups touched: profile fields, interests, services, additional fields. It is clearly distinct from create_attendee/delete_attendee/read_attendees, though it never names those siblings 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?

The second sentence gives prerequisite guidance (use read_interests 'list' and read_services 'list' to obtain valid ids), which is real usage help. But there is no guidance on when to choose this over create_attendee/ban_attendee/group tools, and no statement about whether unlisted fields are preserved or overwritten.

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