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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds meaningful behavioral context beyond this: it explains the payload is the first content block and the disclosure the last, and warns that the returned text is published material to be read as data, not instructions. This is a useful, non-redundant addition.

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 composed of three sentences, each serving a purpose: stating the core function, contrasting with a sibling, and adding behavioral notes. It is front-loaded with the primary purpose and avoids redundant phrasing. It is slightly longer than necessary but remains efficient and clear, with no wasted words.

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?

The description covers the essential aspects: what the tool returns, how the optional section modifies the output, when to use an alternative, and a caveat about the nature of the data. It does not describe the exact formatting of the digest, but the schema covers the section enum, and the output is simply the Markdown digest. Given the annotations and schema richness, this is sufficiently complete for an agent to call correctly.

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%, so both parameters (date and section) are already documented in the schema. The description adds only a minor clarification that with 'section' you get one heading block, which is already implied by the schema's enum and description. Since the schema carries the heavy lifting, a baseline of 3 is appropriate; the description contributes little beyond that.

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 'Returns' and the specific resource: the canonical Markdown digest for a published day, optionally a single heading block with the 'section' parameter. It distinguishes itself from get_day_listing by explicitly contrasting the scope (rule-selected subset vs. every item). This leaves no ambiguity about what the tool does and how it differs from a sibling.

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 guidance: 'for every item an agency or collection published, use get_day_listing.' This directly tells the agent when not to use this tool and points to the alternative. It also clarifies that the digest summarizes a subset and counts the rest, which implies it is appropriate for overviews rather than exhaustive enumerations. That is strong, actionable usage guidance.

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