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

Goes well beyond the annotations: caching window (5 minutes), billing behavior (empty results not charged, non-empty snapshots charged at USD 0.05 with no free tier), latency range (1-2 s typical, up to 20 s), and a prompt-injection warning to treat returned page text as untrusted. Annotations only cover read-only/idempotent semantics, so this is substantial added context.

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-loads purpose and scope, then layers cost, latency, and safety notes. Mostly dense and useful, but the billing sentence is written telegraphically ('Empty/unavailable: not charged; non-empty snapshots charged..') with a doubled period, which slightly hurts readability.

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?

Output schema exists, so return values needn't be explained, yet the description still covers the snapshot size, data exclusions, empty-region edge case, caching, cost, and latency - everything needed to call and interpret it safely. The only real gap is any statement about whether results can be widened beyond 25 (no pagination note).

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% - both `url` and `limit` are already documented with format, example, and range in the schema. The description restates the 25-listing cap and 'one Redfin region', and adds that source_url embeds the street address, but contributes no parameter syntax or constraint beyond the schema. Baseline 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?

Specific verb + resource + scope: 'Search public property listings', returning a 'partial snapshot of up to 25 active and coming-soon for-sale listings for one Redfin region'. It further bounds the domain ('Listing facts only; no owner, agent or contact data'), which no sibling tool covers, so an agent can distinguish it without opening the schema.

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?

Usage is implied rather than stated: the tool works on one Redfin city/county/neighborhood page and returns listings only, which hints at the input shape. There is no explicit 'use this when…' clause, no exclusion of alternatives, and the 'Some regions have none under MLS rules' caveat is a result warning rather than guidance on when to call.

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