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

Annotations already mark this as read-only/non-destructive; the description adds useful context by specifying that the result is a base64-encoded PDF and that a prior login with the matching account_link_id is required. No contradiction with annotations.

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 with the precondition front-loaded before the action. Every sentence carries distinct information: prerequisite, action+output format, and parameter source. No filler.

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 tool with no output schema, the description compensates by stating the output is a base64-encoded PDF, and it covers the only hard prerequisites (prior login and parameter provenance). Between the schema's parameter descriptions and this overview, an agent has enough to call the tool 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?

Input schema covers 100% of parameters with descriptions, so baseline is 3. The description adds acquisition context (where cva_id/rcat_no come from, optional rpt_pkg_pth lookup) but does not redefine the parameters' meanings; the schema remains the primary source.

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 concrete action ('Download an issued certificate as PDF'), identifies the output encoding (base64), and clearly separates this download tool from the sibling apply/list tools by referencing 'issued certificate' and the application-result source. The verb+resource+format specificity is enough for an agent to know what it does.

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?

Explicitly states the prerequisite ('REQUIRES prior hometax__session__login call with same account_link_id') and tells the agent exactly where to obtain cva_id/rcat_no: from hometax__certificate__apply_auto or apply_with_template. It does not explicitly discuss when not to use it or mention the certificate-list alternative, so it falls short of a full 5.

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