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

Annotations already establish this as a read-only, idempotent, non-destructive, closed-world operation. The description adds useful behavioral context by explaining the latest-vs-point-in-time snapshot selection and enumerating the returned metadata, though it does not discuss authentication, rate limits, or error behavior.

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 dense but front-loads the main resource and returned metadata before explaining the `at` parameter behavior. It is appropriately sized for a metadata-returning tool and has little filler, though the first sentence is quite long.

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?

There is no output schema, so the description carries the burden of explaining return values. It does so comprehensively by listing the snapshot fields, conventions, validation summary, available statements, files with hashes, citation format, and point-in-time snapshots reference.

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 are already documented. The description restates the meaning of `at` as a point-in-time selector and does not add meaningful detail about `company` beyond the schema's reference to search_companies. Baseline 3 is appropriate.

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 identifies the resource as a company snapshot and enumerates the metadata it returns, such as as-of period, release date, coverage, conventions, validation summary, statements, and files. It is distinguishable from siblings like get_statement and get_ratios by scope, though it does not explicitly name or contrast those alternatives.

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 point-in-time use of `at` is clearly explained: it selects the snapshot that was latest on a given date. However, the description does not explicitly state when to use this tool versus siblings such as get_statement or get_sources, leaving usage to inference.

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