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

Annotations already declare read-only/idempotent, and the description goes well beyond them: it discloses the result-size budget rationale, the null semantics for score/forecast on completed sprints, that committedPts/completionPct/stories.total are null when unrecorded, and that capacity.perAssignee only counts stories still on the sprint after closing. This is exactly the kind of non-obvious behavior an agent cannot get from structured fields.

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 payload is front-loaded in the first sentence, with the REST-endpoint scope note second and the completed-sprint caveats last. It is slightly dense and long for one paragraph, but each sentence carries non-redundant information.

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 carry return-value meaning, and it does name key fields and their null conditions. It falls short of describing the actual shape of nested results (burndown summary vs capacity vs scope-creep), which leaves some ambiguity for a composite metrics tool, but the critical edge cases are covered.

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?

Only one parameter (sprintId) with 100% schema description coverage, so the schema already does the work. The description adds no format hints or constraints on the ID beyond what the schema states; its added meaning concerns return values rather than the parameter. Baseline 3 applies.

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 ('Compact metrics snapshot for a sprint') and enumerates the contents (burndown summary, capacity totals, scope-creep, blocker count, health score), which implicitly separates it from get_sprint and get_sprint_test_health. It never names those siblings explicitly, so the differentiation is inferential rather than stated.

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 line about full per-day burndown points, cycle-time and cumulative-flow staying on the REST endpoint is an effective 'when not to use this' signal for detail-hungry callers. However, there is no guidance on when to pick this over get_sprint or get_sprint_test_health, which are the closest in-domain alternatives.

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