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

The readOnlyHint annotation already signals a safe read operation. The description adds meaningful behavioral context by explaining the output structure: the claim tested, how the figure supports/challenges it, and why the number is what it is. No contradictions with annotations.

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?

The description is compact and front-loads the core behavior, then adds usage triggers and parameter hints. Every sentence earns its place, though the 'Args: entity; item' line is minimal and slightly telegraphic.

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?

Given four parameters, zero schema descriptions, and a rich sibling set, the description explains the tool's purpose and primary usage well. However, the reading_level parameter and the full response_mode behavior are left undocumented, which is a notable gap for an agent trying to invoke this 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 description coverage is 0%, so the description must carry parameter meaning, but it only briefly mentions 'entity' and 'item'. It clarifies that item=earnings covers revenue, profit and EPS, and that response_mode=plain is for beginners, but it does not explain reading_level or the other response_mode values.

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?

The description identifies a specific action and resource: reading one reported figure against the investment case, and lists what the output contains (claim tested, support/challenge, why the number is what it is). It distinguishes this from siblings like get_thesis or what_changed by focusing on a single figure's impact rather than a general narrative.

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?

Explicit trigger examples are provided: 'what does X's revenue mean', 'what do X's earnings mean', 'how was the quarter'. This gives clear when-to-use guidance, though it does not name alternatives or exclusion conditions.

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