get_fulfillment_stock

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

With no annotations, the description carries the full burden and does well: it discloses the read nature, a significant precondition (Full enrollment), and the error behavior when unenrolled ('Meli answers with an error, which is surfaced clearly'). It omits pagination/rate-limit behavior and any permission/auth detail, keeping it from a 5.

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 sentences, front-loaded with purpose, then routing, then a clearly flagged 'Gotcha' precondition. Every sentence earns its place with 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 read-only list tool with no output schema and one optional param, the description supplies purpose, sibling routing, return content (available and non-sellable quantities), and the enrollment precondition with error behavior. An agent has everything needed to call it 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?

Schema coverage is 100% and the single 'limit' parameter is fully documented in the schema (range 1-100, default 50). The description adds no syntax or format detail beyond the schema, so the baseline of 3 applies.

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 (List) plus resource (seller's stock at Mercado Livre fulfillment centers) and scope (available and non-sellable quantities). It also explicitly names the sibling tools (get_my_items/get_item) it should not be confused with, so an agent can route correctly without opening any 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 when-to-use ('inventory questions about Full'), explicit when-not/alternative ('for regular seller-shipped stock use get_my_items/get_item'), and a precondition ('only works for accounts enrolled in Full'). Nothing is left to inference.

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