ebay_fetch_item_aspects

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

Annotations only declare readOnlyHint, so the description carries the rest and does so richly: gzipped JSON payload, application/octet-stream content type, embedded-resource delivery, gunzip requirement, and a hard failure mode (DownloadTooLargeError above 25 MiB vs eBay's 100 MB source file). This is far beyond what readOnlyHint provides.

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?

Boldly front-loads the primary action (download the aspects), then layers the delivery format, the size limit, and the alternative. All three sentences earn their place, though the middle sentence is dense with parenthetical detail that slightly slows scanning.

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?

No output schema exists, and the description compensates by fully describing what comes back (an embedded gzipped JSON resource with a specific content type and a decompression step) and the conditions under which nothing comes back. Nothing needed to call it correctly is missing.

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 100% and there is only one parameter, so the schema already documents categoryTreeId and its provenance from ebay_get_default_category_tree_id. The description restates the tree concept and the EBAY_US (0) example but adds no new syntax or format detail; 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?

States a specific verb (download) and resource (aspects/item specifics of every leaf category in a category tree) plus the API family (Taxonomy). It distinguishes itself from ebay_get_item_aspects_for_category by scope (whole tree vs per-category), letting an agent tell the two apart without opening either 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 an explicit alternative (ebay_get_item_aspects_for_category for per-category lookups) and the condition that selects it ('especially on large trees such as EBAY_US (0)'). The failure threshold above 25 MiB is stated as the reason to prefer the alternative, which is exactly the routing guidance an agent needs.

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