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

Beyond the readOnlyHint/openWorldHint annotations, it discloses the match method (nearest BDNB building within 200m), the failure mode ('returns null + refunds credits if no building found within 200m'), and the exact cost (2 credits). This is exactly the behavioral context annotations cannot carry.

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 purpose, then labeled sections (Returns, REQUIRED, Match method, Workflow, Example, Cost). The example and cost lines are compact and each sentence carries distinct information with no redundancy.

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 compensates by enumerating the returned fields and showing a sample response shape, and it documents the null/refund edge case. An agent has everything needed to call and interpret the tool.

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 the baseline is 3, but the description adds real meaning: it names the upstream source of transaction_id and shows the expected string shape via an example call. That goes beyond the schema's bare 'DVF transaction ID' label.

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?

States a specific verb+resource ('Get physical building characteristics') and names the exact source database (BDNB) and the triggering entity (a DVF transaction). The listed return fields make it immediately distinguishable from siblings like score_renovation_potential or analyze_building_stock.

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?

Explicit workflow instruction: 'call search_property_transactions first → use an "id" from the results as transaction_id here.' It also tells the agent exactly where to source the required parameter, leaving no inference needed about ordering or prerequisites.

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