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

Annotations declare a non-idempotent write (readOnlyHint=false, idempotentHint=false), and the description adds real behavioral context beyond them: the application is manually reviewed by Wall Marketing, then screens are shipped and the venue emailed, and no email parameter is needed because the signed-in account is used. It could still say what happens to the application after submission (editable/cancellable?) or on rejection.

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?

The purpose is front-loaded in sentence one, which is good. However, the installation walkthrough ('connect the screen to the venue's WiFi, peel the covers off the adhesive and stick it on the wall') and the 20% revenue-share pitch do nothing to help an agent decide or invoke, padding an otherwise focused definition.

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 10-parameter write tool with an output schema, the description covers the review-and-fulfilment workflow, the zero-cost/20%-share commercial terms, and the account-email binding. It omits post-submission lifecycle details (modifying or withdrawing an application), which is a minor gap given the output schema exists.

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%, so all 10 parameters are already documented, including state/suburb fallback and the customers_per_day and requested_screens semantics. The description only adds 'one or more' screens and the signed-in-email implied parameter, so baseline 3 is correct.

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 first sentence names a specific verb and resource ('Apply for one or more free advertising screens at a venue') and scopes the venue types. No sibling tool (host.venue.overview, host.screens.*, advertiser.venues.*) shares this apply-to-host purpose, so an agent can route to it unambiguously.

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 only implied: the description explains what hosting involves and that the application is tied to the signed-in account's email, which is a useful precondition. It never says when to use this versus host.venue.overview or the advertiser.venues tools, and gives no when-not guidance.

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