set_cookie

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

No annotations are provided, so the description carries the full burden. It does disclose a meaningful trait — 'memory only, never logged' — which tells the agent the value is not persisted or written to logs. However, it omits whether the cookie overwrites existing auth, whether it is validated before use, and what happens on an invalid value.

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?

Purpose is front-loaded in the first sentence, with the parameter detail following in a compact args block. No filler, though the trailing format examples are slightly verbose.

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 explained. For a credential-setting tool with no annotations, the description still leaves gaps: relationship to sibling auth tools, overwrite behavior, and failure modes.

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, and it does: it explains the parameter is the full session cookie value and gives two concrete formats ('session=abc...' and 'name=..; session=..'). This meaningfully clarifies what string to pass.

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 action and resource: setting a session cookie used for authentication. It is clear what the tool does, but it never distinguishes itself from close siblings like set_token or login, which an agent must choose between in this toolset.

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?

There is no guidance on when to use this versus set_token or login, no prerequisites, and no statement about whether it replaces existing credentials. The phrase 'for authentication' implies context but gives no selection criteria.

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