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

Annotations already establish the safe read-only profile (readOnlyHint=true, destructiveHint=false), so the burden is lower. The description adds value beyond them by enumerating the returned attributes (name, title, type, read-only flag) and naming the underlying endpoint, so the agent knows the shape of what comes back despite there being no output 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?

Two short sentences with zero filler: the resource and its scope lead, the follow-on usage note follows, and the endpoint tag closes. Every clause carries information an agent can act on.

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?

For a zero-parameter list call with no output schema, the description supplies the essential missing piece — what each field record contains — and a usage pointer. It does not mention ordering, pagination, or caching, but for a small metadata listing those are likely non-issues, so it is complete enough to call 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate. Baseline 4 applies — no parameter guidance is required and none is missing.

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+resource (list person fields) and scopes it precisely: built-in and custom, with the exact attributes returned. This is clearly distinguishable from siblings like encharge_list_segments, encharge_list_segment_people, and encharge_get_people, which the agent can rule out without opening a 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 a concrete downstream usage pointer — "Use the names in encharge_upsert_person" — which tells the agent why it would call this and how the output feeds another tool. It does not state explicit exclusions or when-not-to-use, but there is no competing sibling that lists fields, so the missing comparison costs little.

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