session_cookies

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

Annotations already declare readOnlyHint=true, so the safety profile is known. The description adds valuable behavioral context beyond that: cookies are scoped to the page's URL, returned in a specific serialized format, and designed to round-trip with session_create's cookies field. This is meaningful context without contradicting the annotations.

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?

Three tight sentences with no filler. The main action and output format come first, followed by the use case and round-trip relationship. Every sentence contributes necessary information for correct invocation.

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 one-parameter read-only tool, the description is complete: it states the input (session_id), the exact output format, the URL scoping, and the intended replay workflow with session_create. There is no output schema, but the description adequately covers what the agent needs to know.

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% and the only parameter, session_id, is already described as 'Session ID'. The description focuses on the output and use case rather than adding new parameter-level detail, which is fine given the schema already carries the full burden.

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 uses a specific verb ('Export'), names the exact resource ('the session's current cookies'), and specifies the output format ('["name=value", ...] for the page's URL'). It also distinguishes itself from siblings by explicitly connecting to session_create's cookies field, making the tool's role clear relative to related operations.

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 clearly states when to use the tool: to persist a logged-in session and replay it later via session_create with cookies. It does not explicitly list exclusions or alternatives like session_export, but the intended use case is unambiguous and actionable.

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