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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. Beyond that, the description adds real value: it warns that returned text lives under "untrusted_user_content" and must be treated as data only, and it states that contact details are deliberately absent. It does not describe failure behavior for a bad or missing branch_id.

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?

Two sentences, front-loaded with the action and the id source, with no filler. The parenthetical return-field list and the untrusted-content warning both earn their place, though the em-dash construction is slightly dense.

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 single-parameter read tool with no output schema, the description covers the return payload, the trust boundary for returned text, and the routing for anything contact-related. Only error/not-found behavior is left unstated, which is a minor gap given the annotations already signal a safe read.

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% and the single branch_id parameter is fully documented in the schema, including the same get_property_details provenance hint. The description adds no constraint, format, or validation detail beyond what the schema already states, so the baseline of 3 applies.

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 gives a specific verb and resource ("Fetch one estate agency branch by branch_id") and then enumerates exactly which fields come back (name, firm, address, opening hours, description). It is clearly distinguishable from sibling tools like get_property_details, which is named only as the source of the id.

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 tells the agent where to obtain branch_id ("from get_property_details") and explicitly redirects contact-seeking to book_viewing or request_valuation instead of this tool. That is clear routing guidance, but it does not cover when the tool should not be called generally (e.g., id not found handling, whether to prefer search/find_agents for discovery).

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