set_prereq

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

Beyond the annotations (readOnlyHint=false, idempotentHint=true), the description discloses that values are persisted and override environment defaults, that secrets are not stored, and that only presence flags are used for credentials/LLM key. This adds meaningful behavioral context that the annotations alone do not provide, with no contradiction.

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 description is compact and front-loaded: purpose, security boundary, usage context, and persistence behavior are each covered in a few short lines without fluff. Every sentence adds necessary operational information, and the structure is scannable.

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?

Given the 11 optional parameters and 0% schema coverage, the description handles the core usage well: what to store, what not to store, when to pass Zeus context, and how flags behave. It falls slightly short on fully explaining the remaining parameters (mode, role, collection, auth_mode), though an output schema exists and no parameters are required.

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%, so the description must compensate. It adds valuable semantics for zeus_url/bucket/scope and clarifies the has_* presence flags, but it does not explain the meaning of mode, role, collection, or auth_mode. With 11 parameters, this partial coverage leaves a clear gap even though the most important parameters are addressed.

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 clearly states the verb/resource ('Store non-secret prereqs for readiness') and immediately disambiguates what it does not do ('does not store password/token values'). It ties the stored values to downstream consumers ('readiness/doctor'), making it distinct from sibling tools like readiness_check or doctor.

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?

The description gives explicit when-to-use guidance: pass user-named zeus_url/bucket/scope instead of Helper localhost defaults, and put real secrets in environment variables. It also explains the override behavior ('Persisted values override MCP host ZEUS_* env defaults') and limits the presence flags to credentials/LLM key, leaving no ambiguity about when this tool should be called.

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