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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds that suggestions are anonymous and that a three-character minimum applies, which is useful behavioral context, but says nothing about pagination, result counts, or rate limits.

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, front-loaded with the core action followed by routing guidance. Efficient and waste-free, though the first sentence packs several clauses that could be trimmed slightly.

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?

With only one parameter, an output schema (so return values need not be explained), and clear annotations, the definition is nearly complete. It omits any note on result limits or date relevance, but nothing needed to invoke 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 the single q parameter is fully documented in the schema, including the 3-character minimum and suggestion types. The description's mention of 'at least three characters' restates the schema rather than adding new meaning, so the 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 and resource ('Fetch MLB's anonymous typeahead suggestions') plus the qualifying constraint (at least three characters) and the suggestion categories. It also names the sibling tools it is distinct from, so an agent can place it 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?

Explicitly routes to alternatives: mlb_player/team tools for a selected entity, and mlb_discovery for query selectors. This tells the agent when not to use this tool. The positive trigger is only implied (typeahead/autocomplete use), so not quite a full when/when-not pair.

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