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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds a genuine behavioral trait not in structured data: rows are keyed by team id rather than team name, which forces a follow-up lookup.

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 short sentences, zero waste, and the scope (per-team, last N days) is front-loaded before the id-resolution tip.

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 must sketch the return shape; it does so via 'same metrics as get_agent_report' plus the row-keying note, and the fields enum supplies the metric names. Adequate, though a brief word on response format would make it airtight.

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% — the days parameter even spells out the inclusive window and default, and fields has its enum inline — so the schema carries the parameter burden. The description adds only an indirect hint about the id field via the row-keying note.

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 the resource and scope precisely ('Per-team performance over the last N days') and differentiates itself from the agent-level sibling by referencing get_agent_report, so an agent can tell team-level from agent-level reporting. It is a noun phrase rather than an explicit verb+resource sentence, which keeps it just short of 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?

Gives actionable workflow guidance: call list_teams to resolve the team ids that key the rows. It also implicitly frames the choice against get_agent_report by declaring identical metrics at team granularity, though it never states an explicit when-not condition.

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