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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds the useful semantic that results are a diff against the previous daily build, but says nothing about auth, rate limits, or result shape beyond the diff framing.

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?

A single compact sentence with the scoping constraint ('since the previous daily build') front and center; nothing is wasted. It reads as a noun phrase rather than a full statement, but the economy serves the reader.

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?

With no output schema, the description does partially carry the return-value burden by naming the diff categories, which is helpful. However, it leaves the feed enum unexplained and gives no routing versus feed_list, so an agent cannot fully resolve how to call it 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 coverage is only 50%: the date parameter is documented as 'YYYY-MM-DD, default newest', but the four enum values for feed (domain-ranks, kevscope, riskroll, form4) are unexplained in both schema and description. The description's 'one feed' hints that feed selects a single source but does not tell the agent which value corresponds to which dataset.

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?

States a specific resource (one feed) and a precise scope (rows added/removed/changed per file since the previous daily build), which is far more informative than the title. It does not, however, differentiate itself from the sibling feed_list, leaving the agent to guess which of the two to pick.

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 when-to-use statement, no prerequisite, and no reference to the sibling feed_list. The only hint of usage is the implicit 'since the previous daily build' framing, which the agent must infer.

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