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

Annotations already declare readOnlyHint and destructiveHint=false, so safety is covered. The description adds real behavioral information beyond that: only active threads are returned and resolved history is excluded, which directly affects what the agent can conclude from an empty result. It omits ordering and pagination, keeping it short of a 5.

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 sentences, zero filler, and the scope constraint is front-loaded immediately after the core action. Every sentence earns its place.

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-shape detail is unnecessary, and annotations cover the safety profile. The remaining gap is whether replies to resolved parents appear, and whether results are paginated or ordered — minor but relevant for a listing tool.

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?

There is one parameter (projectId) with 0% schema description coverage, so the description must compensate. "Project comments" implies the id scopes the listing to a project, but it adds nothing about format, requiredness, or behavior for invalid ids. With a single, obvious parameter and a uuid format in the schema, baseline 3 is appropriate.

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 active project comments and their replies") and adds a scope qualifier that separates it from generic listing tools. It does not explicitly contrast with siblings such as list_chat_messages or list_files, but the resource noun is distinct enough to disambiguate.

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 sentence "Resolved comment history is not returned by this tool" gives an implicit when-not, and the word "active" signals the intended scope. However, no alternative tool is named for retrieving resolved threads, so the agent must infer where to go next.

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