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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the related-vs-complementary framing, but discloses nothing about result limits, ranking behavior, or fallback behavior when a handle has no matches. With annotations carrying the safety burden, this is adequate but thin.

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 tight sentences: purpose first, then the prerequisite routing guidance. No filler, no repetition of schema details, and the core action 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?

An output schema exists, so return values need no explanation. Combined with 100% schema coverage and readOnly/openWorld annotations, the description supplies the remaining gap: what the tool produces and how to source its required input.

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 the schema already documents handle, limit, and the related/complementary intent values with defaults and bounds. The description echoes the handle concept and the two recommendation modes but adds no syntax or constraint detail beyond the schema. 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 ('Fetch') and resource ('related or complementary Allbirds products for a product handle'), and explicitly names sibling tools for finding the seed product vs. predictive search. An agent can distinguish it from allbirds_product, allbirds_products, and allbirds_search_suggest without opening a 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?

Clearly directs the agent how to obtain the required seed handle ('Use allbirds_product or allbirds_products to find source products, or allbirds_search_suggest for predictive search matches'). It provides strong prerequisite context but does not state when recommendations should be avoided or preferred over direct product lookups.

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