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 what the hits contain (rarity and best-standing-listing details), which is useful behavioral context, but says nothing about auth prerequisites, rate limits, or pagination. With annotations carrying the safety signal, this is a modest add.

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 sentences, zero filler. The core capability is front-loaded and the routing guidance to siblings follows immediately, so nothing is buried.

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?

A read-only search tool with full schema coverage, an output schema, and annotations covering safety and open-world behavior. The description supplies the one missing piece agents need for selection: the sibling routing. Only minor gap is no mention of pagination behavior for the limit param, which the schema already describes.

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 all three parameters (identifier, query, limit) are already documented in the schema. The description's 'by keyword' and 'wallet's holdings' loosely map to query and identifier but add no syntax, format, or default detail beyond what the schema states. Baseline 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?

Specific verb+resource+scope: 'Search a wallet's NFT holdings by keyword' names the action, the corpus (wallet's NFT holdings), and the filter (keyword). It explicitly distinguishes itself from the two closest siblings, so an agent can pick it 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?

Names two concrete alternatives and the condition that selects each: opensea_profile_items for listing all holdings, opensea_collection_search_items for searching within a collection. Combined with the stated scope (keyword search over a profile), the when-to-use decision is fully determined.

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