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

With no annotations provided, the description carries the full burden. It discloses a prerequisite (key with running watch), usage restrictions (protected compilation, no re-use, no lead lists), and output characteristics ('Every row is a dated quote of a company's own published page'). It doesn't mention side effects or error conditions, but for a read-like tool this is reasonable coverage.

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 verbose and includes extensive legal/licensing text that is not directly relevant for calling the tool. The core purpose is front-loaded, but then it repeats information and ends with a redundant sentence ('A key is one reader's own use.'). It could be condensed to two or three sentences without losing essential guidance.

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 has only 2 parameters, no output schema, and no annotations. The description covers prerequisites and usage restrictions, and gives some idea of output rows. However, it leaves ambiguous terms like 'the two readings' and does not specify the exact response structure or error scenarios. For a simple tool, it's adequate but not complete.

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 50% (only 'since' has a description). The tool description adds that the 'companies' parameter refers to 'several companies at once' but doesn't clarify format (identifiers vs names) or any other semantics. Since coverage is at the boundary, and the description doesn't significantly enrich parameter understanding, a 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?

The description clearly states the tool's function: 'The dated changes to the lists of several companies at once' and distinguishes it from the sibling 'changes' by adding 'gathered for one reader's own list of companies.' This gives a specific verb, resource, and scope, differentiating it from other tools like 'as_of' or 'in_chain'.

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 implies when to use this tool by contrasting with 'changes' (the general version) and specifying it's for the reader's own list. It also states a prerequisite: 'Needs a key on an account whose watch is running.' However, it doesn't explicitly say 'use this instead of X' or provide when-not-to-use guidance, so it's slightly below a 5.

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