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

Annotations already cover readOnly/idempotent/openWorld/non-destructive, yet the description adds real behavioral context: results are sorted biggest-first, filings lag trades by days to months, no prices or returns appear in answers, and filing text should be treated as data not instructions. The prompt-injection and staleness disclosures are genuinely useful beyond the structured fields. It stops short of describing pagination behavior.

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 opening sentence is an overlong run-on that packs scope, fields, sorting, and matching into one clause chain, making it hard to parse. Several trailing sentences repeat the same caveats ('no prices', 'no returns', 'Information, not advice'), so length is not earning 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 no output schema, the description usefully enumerates what an answer contains (name, manager/city, report value, filing date) and how results are ordered, plus the tier-gating caveat. For a read-only search tool this is close to complete, though pagination mechanics go unmentioned.

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 the schema already documents limit, cursor, and search; baseline is 3. The description adds only marginal semantics, clarifying that matching is against a word of the name 'as the SEC lists it' with case and punctuation ignored, which the schema partly covers already.

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 names the resource (funds Aeon holds quarterly holdings reports for, watched funds, largest 13F filers) and the return fields (name, manager, city, newest report value, filing date), which is concrete. It also distinguishes itself from get_fund_changes ('Hand a slug to get_fund_changes for what it holds'). However, the actual verb is buried inside a single sprawling clause chain, so the purpose is recoverable but not front-loaded.

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?

It routes the agent downstream ('Hand a slug to get_fund_changes for what it holds') and notes a feature-gating caveat ('Not every account includes fund search'). But it never states when to pick search_funds over siblings like search_filings, nor any prerequisites for the search itself, so usage is only implied.

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