get_cost_trend

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

With no annotations, the description carries full burden. It discloses that the tool is paid (PREMIUM), returns real schedules (not projections), and only works for jurisdictions with multiple dated schedules. It does not mention idempotency or rate limits, but the paid nature and data constraints are well-covered.

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 longer but each sentence adds value: purpose, constraints, usage guidance, and payment info. It front-loads the core action. Could be slightly tightened, but overall effective.

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 no output schema and moderate complexity, the description adequately explains what the tool returns (history, delta, CAGR) and its limitations (only where multiple schedules exist). It covers the paid nature and parameter options, making it complete for an agent to decide whether to use 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?

Schema coverage is 100%, so baseline is 3. The description adds 'Pass jurisdiction or address' which reinforces mutual exclusivity, but the schema already says 'Provide this OR address.' No additional parameter semantics beyond the schema are provided.

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 retrieves the real dated revision history of a jurisdiction's headline development fee, including prior years' figures and future adopted steps, with delta and CAGR. This distinguishes it from sibling tools that estimate costs or compare jurisdictions.

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 when to use (to budget fee based on future permit pull date), explicitly says 'NOT a forward projection', and notes that it only returns data where the city publishes multiple schedules. It also mentions payment via x402 or prepaid key. However, it does not directly contrast with all sibling tools.

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