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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds the data grain ('one per learner per course') and the in-progress/completed states, but says nothing about pagination behavior or ordering beyond what the schema already states.

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, with the purpose and data grain front-loaded ahead of the filtering hint. Minor redundancy: 'in progress or completed' restates the status enum and the same information appears in the output 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?

An output schema exists so return values need no explanation, parameters are fully documented in the schema, and annotations cover the safety profile, leaving little for the description to carry. The only real gap is routing against the sibling get_completion, which an agent must infer from the singular/plural naming.

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%, so every parameter (limit, offset, status, courseId, identityId, identityExternalId) is already documented in the schema, including defaults and paging semantics. The description's filter sentence restates a subset of that without adding format or behavioral detail, so the 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 (lists) and resource (learner runs), and defines the unit of the resource ('one per learner per course') along with the fields returned. It does not explicitly distinguish itself from the singular sibling get_completion, so it falls 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?

The closing sentence 'Filter by course, learner or status' implies how to narrow results, which is implied usage rather than explicit guidance. There is no statement of when to use this instead of get_completion or list_identities, and no prerequisites are given.

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