explain

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is established. The description adds useful output context (trajectory, ratchet mark, and that brief adds fuller context), but it does not go deeper into behavioral details such as how runs are ordered or what exactly the ratchet mark represents.

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 sentences with no filler. The first sentence defines the output scope, and the second provides usage guidance plus the sibling alternative. Every sentence earns its place and the key information is front-loaded.

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?

For a simple read-only lookup tool, the description covers what the tool returns, why to use it, and how it differs from a related sibling. The params are fully documented in the schema and the annotations cover side effects. It could name the return format more explicitly, but an agent has enough to invoke it correctly.

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 the parameter descriptions already document name, path, and repo well, including matching behavior for 'name' and defaults for 'repo'. The tool description itself adds no parameter-specific semantics, so the baseline of 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?

The description states a specific resource ('one function's score trajectory across runs plus its ratchet mark') and a clear use ('see whether a function is improving or decaying'). It also distinguishes itself from the sibling 'brief' by noting that brief adds full context around the newest score, so an agent can tell them apart.

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 gives explicit guidance on when to use the tool ('Use it to see whether a function is improving or decaying') and points to 'brief' as the alternative for full context. It does not discuss other siblings, but the main decision point is covered.

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