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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds real context beyond that: the required 'activity' scope, the HTTP endpoint, and the shape of the response including paging fields – none of which is in the annotations or schema.

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, front-loaded with purpose, then prerequisite and endpoint, then return shape. Every sentence carries information not available elsewhere, with no filler.

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?

There is no output schema, so the description usefully names the return fields (count, total, next_offset, items) and explains how to continue paging. Combined with full schema coverage and annotations, an agent has enough to call and page correctly; only the sibling-routing guidance is absent.

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 six parameters are already documented in detail; baseline would be 3. The description earns an extra point by explaining the paging contract concretely – 'pass next_offset as offset for the next page' – which links the return value to a parameter in a way the schema cannot.

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 gives a specific verb plus resource ('List activities') and disambiguates the domain term with a parenthetical ('the kinds of work that hours are booked on'). It does not distinguish itself from plausible siblings such as list_services, list_efforts or list_working_hours, which an agent could easily confuse with 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?

It states the prerequisite ('Needs the "activity" scope') and the underlying endpoint, which implies a straightforward read-only listing. There is no explicit guidance on when to pick this over list_efforts or list_working_hours, and no exclusion or alternative-routing statement.

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