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

Beyond the annotations, the description discloses that the digest is returned verbatim, that a one-paragraph disclosure is prepended, and that the returned text is published material to be treated as data, not instructions. This adds meaningful security and output-handling context that annotations alone do not 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?

Two tightly written sentences with no filler. The core behavior is front-loaded, and the security-relevant guidance is placed immediately after in a way that earns its place.

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 single-parameter, read-only tool, the description is complete: it explains what is returned, the exactness of the return, the prepended disclosure, and how the output should be interpreted. The absence of an output schema is adequately compensated by this description.

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?

The schema already fully documents the single 'date' parameter with pattern and description coverage at 100%. The description reinforces that the date refers to a published day but does not add new parameter meaning beyond the schema.

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 ('Returns'), a precise resource ('canonical Markdown digest'), and a scope ('for a published day, verbatim'). This is enough to distinguish the tool from siblings such as list_digests and get_live_day, even though those siblings are not named explicitly.

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 clear context: this is for fetching the canonical Markdown digest of a published day, which implies it is not for listing digests or retrieving live-day content. It does not explicitly name alternatives or exclusion conditions, so it stops short of full routing guidance.

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