get_durability_indices

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 value beyond that: it discloses the failure mode ('or why it cannot be evaluated') and an explicit negative constraint ('No GPS is returned'), which prevents a wrong expectation about return content.

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 zero filler; the primary output content is front-loaded and the two caveats (failure case, no GPS) follow compactly. Every clause carries 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?

An output schema exists, so return values need not be detailed, and annotations cover the safety profile, making the short description mostly sufficient. The remaining gap is the opaque 'file' parameter, and there is no hint about how a run is identified or what happens with an unknown file.

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 0% for the single required parameter 'file', so the description must carry the meaning and it does not. 'For one run' weakly hints that 'file' identifies a run, but it never clarifies whether this is a path, a run ID, or a formatted identifier, leaving the only parameter effectively undocumented.

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 states a specific verb ('Return') and enumerates the concrete outputs (drift, magnitude, onset, gate status) for a single run. 'For one run' implicitly separates it from the sibling list_durability_runs, but it never names or contrasts with get_durability_trend, so sibling differentiation is only partial.

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?

Usage is implied by 'for one run' (single-run lookup rather than listing or trending), but there is no explicit when-to-use/when-not statement and no reference to the sibling tools as alternatives. An agent must infer the routing from the phrasing.

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