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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuine context beyond them: the auth requirement ('Needs the user's Cotlet API key with access to this app') and the semantic rule that opportunities are paid separately and excluded from this budget.

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?

Front-loaded with the core definition before the auth note, and each sentence carries information. It is slightly long at four sentences for a no-param read, but nothing is padding.

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?

For a parameterless read tool with safety annotations and no output schema, the description supplies the return fields, the reset semantics, the scope boundary versus opportunities, and the auth prerequisite. An agent has everything needed to call and interpret it.

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?

The schema has zero parameters, so there is no parameter semantics to document and the baseline is 4. The description correctly implies a no-argument call (account-level budget), adding nothing but leaving no gap.

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 states a specific verb (get) and resource (weekly lead budget) and enumerates exactly what is returned: the weekly budget, spend so far this week, and the reset day. It cleanly distinguishes itself from the sibling mutation 'set_weekly_budget' and from opportunity-related siblings by scoping to budget/spend.

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 explains the concept (budget limits lead spend, opportunities are excluded) which implies when this number matters, but it never explicitly tells the agent when to call this versus alternatives like set_weekly_budget or list_opportunities. Usage is inferable but not stated.

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