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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile needs no restating. The description adds genuine context beyond them: the return is plain text from llms.txt and repeated calls are wasteful within a session. Minor gap: it doesn't say roughly how large the index is or what sections it contains.

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?

Three short sentences, each doing distinct work: what it returns, when to call it and what it feeds, and the anti-pattern to avoid. The most decision-relevant information (purpose plus follow-up routing) is front-loaded.

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 an output schema present, the description need not explain return structure, and with no parameters and full annotation coverage there is little else to disclose. Everything an agent needs to decide to call this first and then branch to the sibling tools is present.

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?

Zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. It correctly implies a no-argument call by describing the output rather than any input.

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 verb and resource ('Get a high-level, machine-readable index of BANKSapi documentation') and pins down the payload ('Returns the plain text contents of llms.txt'), which distinguishes it from get-banksapi-docs-page and get-banksapi-openapi-spec. An agent can identify this as the entry-point/index tool without opening the schema.

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?

Gives explicit timing ('at the start of a session'), two concrete purposes (discover key docs endpoints, seed follow-up calls), names the downstream alternatives 'search-banksapi-docs' and 'get-banksapi-docs-page', and adds an explicit exclusion ('Avoid repeated calls within the same session').

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