Errors per hour

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

Annotations already declare read-only, idempotent, non-destructive behavior, so the description only needs to add what they don't cover. It does exactly that by disclosing the default ordering (newest hour first) and the returned fields (hourly totals, affected-user counts, links). Pagination behavior is left to the 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?

One tightly written sentence plus a usage clause; the return contents and default ordering are front-loaded before the guidance, and nothing is redundant.

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?

No output schema exists, so the description usefully enumerates what comes back, which is what an agent needs here. The remaining gaps (paging continuation, application scoping) are already fully handled by the schema.

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%, with every parameter documented including enums, defaults and paging.nextPage guidance, so the baseline is 3. The description only echoes the date-time format already given in the schema's startDate/endDate descriptions and adds no new parameter meaning.

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: hourly error totals with affected-user counts and TrackJS links, and names the underlying endpoint GET /errors/hourly. It is clearly distinguishable from errors_by_day, but that distinction comes mainly from the name rather than the prose.

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?

"Use to pinpoint when a spike started" gives a concrete selection condition, and the date-time guidance tells the agent how to narrow the window. It does not name an explicit alternative (e.g. errors_by_day for trends) or state when not to use it.

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