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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so safety and external-lookup behavior are covered structurally. The description adds only that the return value is a ticker symbol for downstream use; it says nothing about multiple/ambiguous matches, empty results, or how the limit interacts with disambiguation. Adequate but thin beyond what annotations provide.

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 short sentences, zero filler, with the core purpose front-loaded and the routing hint second. Every clause earns its place.

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 an output schema present, the description needn't explain return values, and it does cover purpose, entry-point role, and downstream usage for a simple two-parameter read tool. Only minor gaps remain around ambiguous or empty search results.

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%, with both `query` and `limit` documented in the schema itself, so baseline is 3. The "Apple → AAPL" example adds a little meaning about input format, but the `limit` parameter and partial-ticker behavior get no elaboration in the description.

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 ("Searches for a stock ticker symbol by company name") and immediately anchors it with a concrete example ("Apple" → AAPL). It also differentiates itself from siblings by naming stocks_get_quote and stocks_get_chart as consumers of its output.

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?

"Start here for Stocks" is an explicit entry-point instruction, and the sentence names the exact alternatives (stocks_get_quote / stocks_get_chart) plus the dependency condition that selects them. An agent knows both when to call this and what to do next without opening any schema.

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