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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds that retrieval is by exact reference, that omission triggers defaults, and that legacy tests are supported, but says nothing about pagination behavior despite limit/offset params.

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 tight sentences with the core operation front-loaded; the legacy-tests note is a useful trailing caveat rather than padding. Little wasted text.

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?

The existence of an output schema removes the need to describe return values, and annotations cover safety. But with 6 parameters at 17% schema coverage, the description leaves testId/limit/offset undocumented and gives no when-to-use routing against transcript/list siblings, so it is only minimally complete.

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 only 17% (just blockId), so the description must carry the load, and it only partly does: it clarifies 'exact ref' and the block/run-sourcing plus defaults. The required testId, plus limit and offset, are left completely unexplained in both schema and description.

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?

The description gives a concrete verb+resource ('Read a human session, task and transcript by exact ref'), which clearly separates it from the plural sibling list_human_sessions. It stops short of naming the natural alternatives (get_transcript, list_human_sessions), so sibling differentiation is implied 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?

It tells the agent to source block/run IDs from list_test_blocks and that omitting them falls back to documented defaults, which is real usage context. However it never states when to choose this tool over get_transcript or the list variants, leaving the main routing decision to inference.

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