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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds substantive context beyond them: a hard result cap ('At most 50 cases'), the tag-based indexing dependency that silently excludes older cases, and the interpretation caveat that an uncovered object is a gap rather than proof of safety.

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?

Front-loaded with a WHEN label and trigger list before the mechanics, and every sentence carries information. It is dense and somewhat crowded by the bilingual trigger phrases, but nothing is redundant with the schema.

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 return burden and does describe the two result components (matched cases per object, list of uncovered objects) plus the 50-case cap. It does not say what fields each returned case carries, which is the only remaining gap for a read tool of this complexity.

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%, so the baseline is 3, but the description adds real semantics: it explains that each object maps to an obj:<object> tag and that values should come from the pull request or find_change_impact. That is meaning beyond the comma-separated format the schema already documents.

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: 'Finds the Test Case work items tagged obj:<object>' and additionally reports uncovered objects as coverage gaps. This is clearly distinguishable from siblings such as ado_create_regression_suite (creates suites) or ado_test_status (reports status).

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?

A dedicated WHEN line plus concrete trigger phrases ('which tests cover SalesLine', 'regression tests for PR N') make the intended moment of use explicit, and it names ado_create_test_plan as the source of the obj: tags. It stops short of naming an alternative tool to use instead when the tags don't exist, so no true when-not guidance.

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