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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is fully covered without the description. The description adds nothing behavioral beyond that: no pagination or limit semantics, no date-window behavior, no scoping rules for the optional filters.

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?

A single front-loaded sentence with no filler, which is good structure. It is arguably too terse for a six-parameter tool with no schema documentation, but there is no wasted text.

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?

An output schema exists, so return values need not be explained, and annotations cover safety. However, with six undocumented filter parameters and no usage guidance, the description leaves genuinely needed call-time information (date filtering, vendor matching, limit behavior) unstated.

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 0% across six parameters, so the description carries the full burden and largely fails. 'One or more properties' loosely hints that property_ids/portfolio are filtering inputs, but vendor, start_date, end_date, and limit are never explained — an agent cannot tell date format, whether vendor is exact-match, or how limit interacts with defaults.

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 ('List vendor bills'), and the parenthetical '(AP invoices)' disambiguates it from sales/AR invoices and other financial siblings. It states the scope ('for one or more properties') but does not explicitly differentiate itself from neighbors like analyze_aged_payables or download_invoices.

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?

There is no when-to-use guidance, no mention of prerequisites, and no routing to alternatives such as analyze_aged_payables for aging analysis or download_invoices for attachments. The agent must infer usage purely from the name and the surrounding tool list.

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