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

Annotations only declare readOnlyHint=true, so the description carries most of the behavioral burden and does so well: it discloses that backtraces are silently truncated to the first 5 frames, that the default sort is last notice, and that filtering can be scoped to deploy/archived/muted/creation time. It does not disclose pagination defaults or rate limits, which the schema partially covers.

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?

Compact for the amount of information conveyed: scope first, then return fields, then sort/filter behavior, then truncation caveat, then the raw API endpoint. A few clauses (the parenthetical UI alias, the endpoint line) could be trimmed, but nothing is wasted.

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 compensates by enumerating exactly what each group carries (id, resolved flag, type/message/backtrace, context, last notice time, notice counts, last deploy). Combined with the truncation caveat and sort/filter semantics, an agent has everything needed for a 10-parameter list call.

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 the baseline is 3. The description adds light semantic framing — it names the order alternatives, describes the filter axes, and clarifies the full_backtraces toggle — but the enum values, defaults, page/limit bounds and RFC 3339 formats are already fully documented in 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 a project's error groups") and immediately maps the Airbrake terminology ("errors" in the app) so the agent can reconcile the API name with the product concept. It also enumerates the returned fields and explicitly differentiates itself from airbrake_get_group ("shows one group in full"), so it is distinguishable from siblings 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?

The description tells the agent to prefer airbrake_get_group when the full detail of one group is needed, and explains that full_backtraces must be set to get every frame — a clear condition/alternative pair. It lacks explicit when-not-to-use guidance (e.g., pagination limits, high-volume caveats), so it stops just short of a 5.

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