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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered structurally. The description adds genuine value by describing the return payload — a 'description' field and a 'summary' with block/condition counts and referenced event names — plus the prerequisite skill load. It stops short of covering pagination behavior or what happens when cohortId does not resolve.

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 and mode, followed by result shape, then search, then the skill prerequisite. Three sentences with little waste, though the clause 'use them for a quick shape of the definition' is mildly redundant after already describing the fields.

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 carries the return-value burden and does so adequately by naming the description and summary fields. Combined with the skill-load instruction and mode explanation, an agent has enough to call it correctly; only pagination and error behavior are unaddressed.

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 baseline is 3, but the description adds intent beyond the schema: it frames 'search' as a discovery mechanism and cohortId as a mode switch between listing and single fetch. It omits any mention of includeDefinitions, so the raw-definition toggle is left entirely to the schema.

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 ('List player cohorts'), parenthetically disambiguates the resource ('dynamic player segments'), and covers the two modes (list vs. fetch one by id). An agent can distinguish it from create_cohort, update_cohort, and get_cohort_members without opening any 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?

Gives clear context: use 'search' to locate cohorts by name or description, set cohortId to fetch a single cohort, and load the cohorts skill first. It does not explicitly name sibling alternatives (e.g., get_cohort_members for membership, create_cohort for creation), so routing guidance is contextual rather than exhaustive.

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