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

Beyond the annotations it discloses that candidates are retained unchanged (no mutation of inputs despite readOnlyHint=false), that operationKey must be persisted before dispatch, that pending/unavailable is provider state and never agent failure, and that scores are ordinal guidance rather than calibrated probabilities. These are exactly the operational traits an agent needs and are not derivable from the idempotentHint/destructiveHint flags.

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 purpose is front-loaded in the first clause, and each subsequent sentence earns its place by adding a distinct behavioral fact (no-mutation, key persistence, recovery, score caveat). It is dense and slightly long, but there is no filler or repetition.

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?

There is no output schema, so the description must carry return-value meaning; it does characterise the scores as selection guidance, which is helpful. However, for such a large, deep input schema it omits any explanation of candidate structure or project/environment scoping, so an agent still has gaps before it can confidently construct the request.

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 17%, so the description has to compensate and it only partly does: it makes clear that criteria are 'explicit' with 'five ordered anchors 0–4' (matching the anchors min/maxItems of 5 and level 0–4) and that operationKey is persisted before the call. It says nothing about the remaining required parameters (projectId, environmentId, candidates) or the rich nested candidate fields (checks, rubric, metrics, sequence, serviceDatasets), leaving most of the schema unexplained.

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 names a specific verb (rank) and resource (scenarios authored by the coding agent), and surrounds it with sibling differentiation: it explicitly says candidates are 'not invented, rewritten, saved as definitions or executed' (distinguishing from firedrill_save_scenario) and points to firedrill_scenario_recommendation as the recovery path. An agent can tell this apart from the save/scenario-listing siblings without opening any schema.

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 frames the call as an 'optional platform evaluation' and names the recovery route via firedrill_scenario_recommendation with the same key/scope, giving clear context for the follow-up. It stops short of stating when not to use it or explicitly contrasting with the other ranking/assessment siblings.

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