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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety and side effects. The description adds value by explaining the time-window scope ('last N days') and exact-match requirement, plus the meaning of common item codes. However, it does not disclose details like result ordering, pagination, or any rate limits. These are not required given the annotations, so a score of 3 is appropriate.

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 concise and front-loaded with the core purpose. It then provides usage examples and a list of common item codes. Each sentence adds meaningful context without fluff, making it highly scannable and efficient.

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?

The tool is simple (3 parameters, no nested objects, no output schema), and annotations are comprehensive. The description fully explains what the tool does, how to use it, and provides useful background on item codes. Even without an output schema, the purpose and behavior are unambiguous, making it complete for agent selection and invocation.

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?

Input schema covers 100% of parameters with descriptions, giving a baseline of 3. The description goes beyond the schema by mapping item codes to real-world events (e.g., 4.02 = restatement, 1.05 = cyber incident), which helps agents understand what values to use. It also reiterates the 'exact match' requirement for the item parameter, reinforcing the schema.

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 clearly states the tool's function: 'Find every 8-K filing in the last N days that declared a specific SEC Item code.' It uses a specific verb ('Find'), defines the resource (8-K filings), and specifies the key qualifier (by item code and time window). This distinguishes it from siblings like sec_8k_recent or sec_8k_today, which likely focus on recency rather than item-based filtering.

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?

The description provides explicit usage guidance: 'Use for cross-market scans like "show me every restatement (Item 4.02) this month" or "every cybersecurity incident (Item 1.05) this quarter".' This clarifies when the tool is appropriate, though it does not explicitly name alternative tools or state when not to use it. The examples sufficiently imply the tool's niche.

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