Draft a readout

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

Annotations already cover the safety profile (readOnlyHint, openWorldHint=false), and the description adds genuinely useful behavioral context that structured fields cannot convey: output may come from client-side sampling or a deterministic template fallback, so results vary in nature across clients. It still does not say whether the LLM path is validated, whether failures fall back silently, or what quality/consistency differences to expect.

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, front-loaded with the primary action and followed by the fallback caveat. No filler, though the line breaks and stray indentation in the source make it slightly less tidy than it could be.

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 tool is simple, one parameter, and an output schema exists so return values need not be explained. However, the nondeterministic-vs-template duality is the tool's defining behavioral trait and the description leaves it ambiguous whether the caller can detect which path was taken or how to force the deterministic one.

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?

A single required experiment_id with 0% schema description coverage; the description does not explain the identifier's form, where to obtain it, or whether it must reference an existing experiment. With only one, self-descriptively named parameter the gap is small, but the low coverage means the description should have compensated and does not.

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 and resource: 'summarize an experiment' producing a readout draft. None of the siblings (power_calc, analyze_lift, check_srm, list_experiments, create_experiment, close_experiment) overlap with summarization, so the purpose is distinguishable without opening schemas, though the description never explicitly contrasts itself with the analysis siblings an agent might otherwise reach for.

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 context is only implied: you call it to get a readout draft for an experiment. There is no statement of when to prefer this over analyze_lift or list_experiments, no preconditions (does the experiment need results first?), and no note on whether an experiment_id that doesn't exist is an error.

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