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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds valuable return semantics beyond annotations: it names the time, accepted, limited, and overQuota arrays and explains that limited means dropped by rate limits and overQuota means dropped over plan quota.

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?

The purpose is front-loaded in the first clause, and the single sentence packs the return structure and aggregation periods without filler. The endpoint sentence adds concise operational context.

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 burden of explaining returns, and it does so clearly with the named arrays and their meanings. Parameters and safety annotations are already covered elsewhere, so an agent has enough to call and interpret the tool 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?

Schema description coverage is 100%, so 3 is the baseline. The description restates the period values already documented in the schema and adds no further meaning for limit, since, or project_id.

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 subject (error volume over time) and scope (whole project), and names the parallel arrays returned. The phrase 'for a whole project' distinguishes it from the sibling airbrake_get_group_stats, so an agent can tell them apart without opening the 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?

No explicit when-to-use or when-not guidance is given, and no alternative tool is named. The scope phrase 'for a whole project' implies usage relative to the group-stats sibling, but the agent must infer that context.

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