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

Annotations already establish read-only, idempotent, non-destructive behavior, so the bar is lower. The description adds real scope knowledge beyond them: figures are computed in the company timezone, phone calls are counted under the phone kind with call counts and answered seconds, costs not fully known are surfaced, and carrier minutes are excluded — all material for interpreting results.

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?

Three sentences, front-loaded with the resource scope and free of filler. The phone-kind sentence is compact but slightly telegraphic, requiring the reader to infer what 'the phone kind' refers to.

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 and zero parameter documentation, the description should explain which company/environment values to supply and roughly what shape the report takes. It covers data scope well but leaves the caller to discover parameter meaning entirely from the JSON 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 description coverage is 0% for two required parameters (a company UUID and an environment enum of staging/production). The description never mentions either parameter, so it does not compensate for the gap left by 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 concrete resource set (all-time and month-to-date credits, pending reservations, monthly usage) with an explicit timezone basis, so the agent knows exactly what data it retrieves. It does not differentiate itself from the many sibling report tools such as summer_reports_service_metrics or summer_reports_commitments, which keeps it below a 5.

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?

There is no statement of when to call this versus the other summer_reports_* tools, nor any prerequisite or exclusion guidance. The content-coverage sentences imply what the report contains but say nothing about choosing it over an alternative.

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