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

Annotations already declare readOnlyHint=true, so the safety profile is covered and the description's job is lighter. It usefully adds the raw Accelo endpoint mapping and the envelope shape of the response, but says nothing about error behavior for a missing/invalid id or about rate limiting.

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, zero filler, and the core identity of the tool is front-loaded before the endpoint and return-shape details.

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?

With no output schema, the description compensates by naming the { meta, response } return envelope, and the tool's surface area is small (2 params, read-only). A brief note on behavior when the id does not resolve would have closed the remaining gap.

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 both id and fields are fully documented in the schema, making 3 the baseline. The description adds no extra semantics for the fields parameter (e.g., cost of _ALL or field syntax) beyond what the schema already says.

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 (Fetch) and resource (a single activity), and enumerates the concrete subtypes (note/email/call/meeting). The word 'single' plus the /activities/{id} endpoint cleanly separates it from the sibling list_activities.

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?

Usage is implied rather than stated: fetching exactly one activity when you already have its id. It never names list_activities as the alternative for enumeration, nor mentions any prerequisites for obtaining the id, so routing is left to inference.

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