spv_documents_download

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context beyond annotations by disclosing the two failure modes and the pending-fetch prerequisite, though it omits local-file overwrite semantics.

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?

Two compact sentences with no wasted wording. The purpose is front-loaded and the failure conditions follow naturally.

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 download tool without an output schema, the description covers what it does, where it writes, and its main failure modes. It could mention the success return value or overwrite behavior, but the key invocation context 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?

Schema description coverage is 100%, so each parameter is already documented. The description only indirectly reinforces that outputPath is a local file path and adds no syntax or format guidance beyond the schema, making the baseline 3 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 gives a specific verb ('Download') and resource ('archived PDF of an SPV document') plus the destination ('local file'). It clearly distinguishes this tool from siblings like spv_documents_get or spv_documents_list.

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?

It states an important precondition: downloading fails with SPV_FILE_PENDING unless the document has already been fetched, and SPV_FILE_PURGED if retention removed it. It does not explicitly name alternative tools or when-not-to-use cases, so it falls short of full routing guidance.

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