Dereference a memory_token in one round-trip

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, but the description adds meaningful behavioral detail: it specifies the response contents ('parsed cell + fact_cid, the full fact body, and the stable fact_url'), and the error behavior ('404 with a typed code if the responder doesn't hold the cid'). This goes beyond what annotations alone provide.

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 well-structured: a clear functional statement, a 'When to use' section, error-handling guidance, and an example. Each sentence contributes distinct information, and it avoids repetitive or irrelevant filler. It is appropriately sized for the tool's complexity.

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?

Despite having no output schema, the description fully describes what the response will contain (parsed cell, fact_cid, fact body, fact_url) and how errors manifest. It also explains the tool's benefit (single round-trip) and fallback options, making the tool's behavior complete for an agent.

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 coverage is 100% (the token parameter is fully described in the schema). The description adds a concrete example argument with a real-looking token, illustrating the exact format. This extra example adds value over the schema description, though the schema is already sufficient.

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 verb ('Parse') and a specific resource ('emem:fact:<cell64>:<fact_cid> citation handle'), and it clearly explains the action: 'return the signed fact body the cid binds.' It also distinguishes from the manual alternative ('saves the agent from string-splitting... and chaining... manually').

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 explicitly provides a 'When to use' section: 'Call when an agent receives a memory_token from another agent (or out of a previous turn) and wants the underlying signed bytes.' It also names an alternative approach: 'try /v1/fetch with the cid then, or paste the token at a mirror.'

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