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

With no annotations, the description carries the full burden and does so: it discloses the live upstream fetch and typical latency (<1s), the presence of a 5-minute cache, data-suppression behaviors ("No phone numbers", private owners unnamed), and the `note` field signaling an inactive listing. That is exactly the mutation/return behavior an agent cannot infer from schema.

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?

Purpose is front-loaded in the first clause and the long field enumeration is doing real work because there is no output schema. It is dense and readable, though the field list borders on exhaustive where a shorter summary of the return shape would suffice.

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?

Two-parameter read tool with no annotations and no output schema; the description compensates by spelling out the full result envelope including the optional `note` and its meaning. Nothing an agent needs to invoke or interpret the response is missing.

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 already 100% with both parameters documented, so baseline 3 applies; the description adds a bit by reinforcing that `id` comes from gratka_search. It does not explain `no_cache` beyond what the schema says, so it earns only a modest bump.

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?

Opens with a specific verb+resource ("Full details of one Gratka.pl listing") and enumerates exactly which fields come back, which cleanly separates it from the sibling gratka_search. An agent can tell this is the detail-fetch step, not the search step, 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?

"Get the id from gratka_search" explicitly sequences this tool after the search sibling, which is the key routing decision. It does not state exclusions (e.g. when morizon_offer would be preferred instead), so it stops short of full when/when-not coverage.

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